From 43b9d23dd34a9bdb4007d270e9db35491a261d02 Mon Sep 17 00:00:00 2001
From: Jiaxin Wu <jiaxin.wu@intel.com>
Date: Thu, 26 May 2016 09:06:04 +0800
Subject: [PATCH] MdeModulePkg: Fix SNP.Initialize() spec conformance issue

v2:
*Refine the coding style according edk2 community's feedback.

Current SNP UNDI Initialize command does not follow the UEFI Spec
to update the SNP MediaPresent field. The result for the Initialize
command execution check should be:
StatFlags: (1) Monitor the upper two bits (14 & 15) in the field to know
whether the command has been executed by the UNDI (Not started, Queued,
Error, Complete). (2) Check the other field to see if there is an active
connection to this network device (used to update MediaPresent).
StatCode: After command execution completes, either successfully or not,
this field contains the result of the command execution (success or failure).
This patch is used to fix it.

NOTE: If any UNDI driver does not follow the UEFI Spec for the media status
update, it may meet failure with this more conditions check (StatFlags).

Cc: Ye Ting <ting.ye@intel.com>
Cc: Fu Siyuan <siyuan.fu@intel.com>
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Jiaxin Wu <jiaxin.wu@intel.com>
Reviewed-by: Ye Ting <ting.ye@intel.com>
---
 .../Universal/Network/SnpDxe/Initialize.c     | 33 +++++++++++++++----
 1 file changed, 27 insertions(+), 6 deletions(-)

diff --git a/MdeModulePkg/Universal/Network/SnpDxe/Initialize.c b/MdeModulePkg/Universal/Network/SnpDxe/Initialize.c
index 21513752de..63bdf92f55 100644
--- a/MdeModulePkg/Universal/Network/SnpDxe/Initialize.c
+++ b/MdeModulePkg/Universal/Network/SnpDxe/Initialize.c
@@ -1,7 +1,7 @@
 /** @file
  		Implementation of initializing a network adapter.
 
-Copyright (c) 2004 - 2008, Intel Corporation. All rights reserved.<BR>
+Copyright (c) 2004 - 2016, Intel Corporation. All rights reserved.<BR>
 This program and the accompanying materials are licensed 
 and made available under the terms and conditions of the BSD License which 
 accompanies this distribution. The full text of the license may be found at 
@@ -37,6 +37,8 @@ PxeInit (
   VOID                *Addr;
   EFI_STATUS          Status;
 
+  Status = EFI_SUCCESS;
+
   Cpb = Snp->Cpb;
   if (Snp->TxRxBufferSize != 0) {
     Status = Snp->PciIo->AllocateBuffer (
@@ -99,10 +101,30 @@ PxeInit (
 
   (*Snp->IssueUndi32Command) ((UINT64)(UINTN) &Snp->Cdb);
 
-  if (Snp->Cdb.StatCode == PXE_STATCODE_SUCCESS) {
-    Snp->Mode.State = EfiSimpleNetworkInitialized;
-
-    Status          = EFI_SUCCESS;
+  //
+  // There are two fields need to be checked here:
+  // First is the upper two bits (14 & 15) in the CDB.StatFlags field. Until these bits change to report 
+  // PXE_STATFLAGS_COMMAND_COMPLETE or PXE_STATFLAGS_COMMAND_FAILED, the command has not been executed by the UNDI.
+  // Second is the CDB.StatCode field. After command execution completes, either successfully or not, 
+  // the CDB.StatCode field contains the result of the command execution.
+  //
+  if ((((Snp->Cdb.StatFlags) & PXE_STATFLAGS_STATUS_MASK) == PXE_STATFLAGS_COMMAND_COMPLETE) &&
+      (Snp->Cdb.StatCode == PXE_STATCODE_SUCCESS)) {
+    //
+    // If cable detect feature is enabled in CDB.OpFlags, check the CDB.StatFlags to see if there is an 
+    // active connection to this network device. If the no media StatFlag is set, the UNDI and network 
+    // device are still initialized.    
+    //
+    if (CableDetectFlag == PXE_OPFLAGS_INITIALIZE_DETECT_CABLE) {
+      if(((Snp->Cdb.StatFlags) & PXE_STATFLAGS_INITIALIZED_NO_MEDIA) != PXE_STATFLAGS_INITIALIZED_NO_MEDIA) {
+        Snp->Mode.MediaPresent = TRUE;
+      } else {
+        Snp->Mode.MediaPresent = FALSE;
+      }
+    }
+    
+    Snp->Mode.State   = EfiSimpleNetworkInitialized;
+    Status            = EFI_SUCCESS;
   } else {
     DEBUG (
       (EFI_D_WARN,
@@ -234,7 +256,6 @@ SnpUndi32Initialize (
   //
   if (Snp->CableDetectSupported) {
     if (PxeInit (Snp, PXE_OPFLAGS_INITIALIZE_DETECT_CABLE) == EFI_SUCCESS) {
-      Snp->Mode.MediaPresent = TRUE;
       goto ON_EXIT;
     }
   }